Rotatable furnace



Feb. 16, 1965 T EKLUND ETAL 3,169,755

v ROTATABLE FURNACE Filed Sept. 25, 1962 4 Sheets-Sheet l NGI/E BzI/vGrssoN BY EL 0F Fozseea Feb. 16, 1965 r. EKLUND ETAL ROTATABLE FURNACE 4 Sheets-Sheet 3 Filed Sept. 25. 1962 Feb. 16, 1965 T. EKLUND ETAL 3,169,755

ROTATABLE FURNACE 4 Sheets-Sheet 4 Filed sept. 25. 1962 INVENTOR- To@ s TEN E/rL wvo rUnited States Patent O 3,169,755 RQTATABLE FURNACE Torsten Eklund, Yngve Bengtsson, and Elof Forsberg, Suraliamniar, Sweden, assignors to Allmnna Svenska Elektriska Aktiebolaget, Vasteras, Sweden, a Swedish corporation Filed Sept. 25, 1962, Ser. No. 226,057 Claims priority, application Sweden, Oct. 3, 1961,

6 Claims. (Cl. 263-33) The present invention relates to a rotatable furnace which comprises a stand turnable in relation to a baseV The invention relates to a solution of these problems.

One object of the invention is to obtain a furnace construction where a furnace body may easily be lifted away from a stand or the like. This problem is solved by means of arranging a stand tiltable in relation to a base and with a furnace body rotatable in relation to stand and base. Said body is fastened to a roll frame consisting of at least two roll rings suitably laminated and mutually connected by means of transverse members. The roll frame together with the furnace body is axially and radially supported by rolls where at least the rolls for radial support are arranged around the body along not more than 180 of its periphery. In a preferred embodiment of the invention the stand is freely placed on the base against supporting rolls or the like in the latter and, possibly after disconnection from transmission members to the rotation motor of the furnace, is removable from the base. This means a further division of the furnace in several parts without taking into consideration the metallurgical and resistance properties of the furnace( VThese and other advantages of the invention and different detailed embodiments will become clearer Vin connection with the description of the accompanying drawings in which'` FIGURE 1 shows a base with motors for tilting movements, FIGURE 2 the base with applied support, FIGURE 3 with the furnace body applied in the support, FIGURE 4 the furnace seen from the side with the roll frame but without the central furnace body, FIGURE 5 the same furnace with inserted furnace body, FIGURE 6 the furnace in position'for operation, FIGURE 7 a part section through the central furnace body with roll frame, FIGURE 8 a section along the line 3 8 in FIGURE 7, FIGURE 9 a detailed embodiment of the blocking pin according to FIGURE 8, FIGURE l0 a section along the` line 10-10 in FIG- URE 7, and FIGURE 1l a section along the lineV 11-11 in FIGURE 7. Y

In FIGURE l is shown a base with two attached bars 11, in which bearings are placed for driving means from driving motors 12 to a gear wheel block 14 for the tilting movements of the furnace. Onthe bars 11 are placed supporting rolls 13 (two, four or more) for a support or 'bridge 15 (FIG. 2), comprising members for supporting the furnace body with roll frame (see below). InFIGURE 2 is shown the support 15 with two .supporting discs 16 attached tothe stand and resting against the supporting rolls 13 in the base. These sup- ICC porting discs 16 are suitably attached to the stand 15, in the shown case for example by means of shrinking. At the tiltable stand or bridge 15 are attached two gear segments 17 or gear wheels, operating against the gear wheels 14. When the motors 12 rotate in one direction the stand is tilted to one side or the other. Rotation of the furnace is done by means of friction operation (or, gear operation), for example by means of at least two friction wheels 18 driven by a roll motor 19 (FIG. 3) situated outside the stand 15. The roll frame with furnace body is supported also in an axial direction by roll bodies 2i), suitably conical and running freely (idler rollers).

As is clear from FIGURES 4 and 5, the stand is tiltable about from a position with the furnace opening (mouth) 21 upwards (FIG. 5) to a position, not shown, with the mouth 21 downwards. In FIG- URE 4 is shown a braking means 24 operating against the supporting discs 16 or other parts of the stand 15 and driven by a hydraulic servomotor 22 via a lever arrangement 23. Since the stand and the furnace body with roll frame normally balance each other, the stand 15 must be locked when the furnace body is removed, this being accomplished by the mentioned braking means.

The friction rolls 18 for the roll frame with furnace body are driven by means of gears 25 in the stand 15 and via'a so-called swivelling gear wheel bracket (FIG. 3) consisting of at least 3 gear wheels inserted in one of the gear segments 17 of the stand. In this case, the bracket consists of a gear wheel at the driving shaft from the roll motor 19 which is later outside the stand. The driving shaft 30 runs centrally through one of the supporting discs 16 to said gear wheel 26 which in its turn is in engagement with an intermediate gear wheel 27 (or a transmission chain), which in turn is in communication with a gear wheel 28 attached to a turning shaft 29 for the friction rolls 18. At a tilting movement of the stand the gear wheels 27 and 28 in the swivelling gear wheel bracket also tilt and this constructioncauses the driving motor to be placed outside the stand, which from the weight and other points of view is a great advantage. The shaft 30, for example by means of a so-called spline connection, is disconnectable from the gear wheel 26. As may be seen, when the driving shaft has been withdrawn from the opening in the supporting disc and the furnace body taken away together with the roll frame, the stand 15 may be lifted away from the base, which has not been possible with previously known constructions where the turning bearings were Vrigidly mounted in the base or the supporting vmembers connected to this.

Loosely placed in the stand 15 is a roll frame 31 which encloses and may be locked to the furnace body 32.` When the locking member' (see below) has been loosened,the. furnace body may be lifted out of the roll frame in the positions shown in FIGURES 4 and 5 and, as mentioned, the stand must be braked when the furnace body is lifted yout since it is unbalanced at this moment. arranged around the roll frame 31 with the furnace body suitably not more than 180 of itsv periphery. The roll frame with furnace body is supported as mentionedin an axial direction (downwards in FIGURE 5) by the conical supporting rolls 20. In operating position the roll frame with` furnace body may be placed asv shown in FIGURE 6, i.e. somewhat' slanting in relation to the horizontal line and with the mouth 21 directed straight upwards. In operation the furnace shall rotate around the r.mentioned shaft and a blowing4 opening 33, for example for oxygen (known per se) be directed towards 'the melt. An evacuating tube 34 may be connected to the mouth for possible steel degassifying. The roll The supporting yrolls 20 in the stand are 3 frame 31 may be attached tothe furnace body in different ways. The roll frame 31 is formed of at least two rings 34 which in a suitable manner as shown inV FIGURES and 1l may be laminated because of the diiiiculty of casting such a piece in one. These two rings which are intended to be in contact with the friction wheel 18 are mutually connected to a number of cross pieces 40, for example l2 in number (FIGURES 7 and 8). In the furnace body are attached iron supports 35 which are rigidly inserted inthe sides of the furnace body 32. In theV cross pieces in theroll frame are inserted pins 35 loaded with plate springs 37 (see particularly FIGURE 9) which in turn are provided to press the pins into corresponding recesses in the iron supports 35. mined byinternally threaded rings, nuts or the like 38 in the recesses, by means of which the placing of the pins against the iron supports 35 can be determined. When the furnace body 32 is to be taken out of the roll frame 31 a number of rings 38 is first loosened, and thus the pin 36, after which the furnace body is placed in position according to FIGURE 5, remaining rings 38 are loosened together with the relevant pin, after which the furnace body 32 is removed (see dotted part of FIGURE 5 which shows a yoke lifted by a cross member, which lifts away a furnace body, for example for relining or cleaning).

The roll frame may be locked to the stand in different ways, for example by means of braking means 39 applicable against the rings 34 (FIGURE 3)-, for example if the mouth 21 is to be turned downwards, for example at tapping or cleaning, or `also in those positions when the furnace body 32 shall be lifted out of the roll frame. As may be seen, the roll frame is loosely placed in the stand and may be easily lifted. out of it with or without suspended furnace body and it is thus possible to make do with a cross member having less lifting capacity than would be the case with a single construction.

The braking means 24 and 39 may consist of strip or bent iron, for example two in number,`mutually connected with cross sections. Y

As mentioned, the operating position of the furnace is shown in FIGURE 6 and is here applicable for carrying out the so-calledKaldo-process, known per se (Iron and Steel Engineer, February 1960, pages 67-68), i.e. production of steel by means of annealingmalleable iron, supplemented by vacuum treatment of steel.

The above illustrated embodiments are, however, only arbitrarily chosen within a great number of possible modifications. For example,v the idea of the invention may be applied to other rotatable furnaces within the metal and cement industry as well as within the iron and steelV industry, for clinker purposes, etc. Many different alternatives are possible within the scope of the invention which are limited by the claims set Aforth below.

We claim: i Y

f1. Rotatable furnace includinga base, a vstand tiltably The springing and movement of the pins are deterstand and roll frame having cooperating roller means axially and radially supporting the roll frame and furnace body, the roller means for radial support being arranged around the furnace along not more than 180 of its periphery, said roll frame and said furnace body having cooperating spring loaded releasable means and recesses in which said releasable means engage to fasten the furnace body in the rollframe.

2. Rotatable furnace including a base, a stand tiltably mounted on the base, a furnace body, and means rotatably mounting the furnace body in said stand, comprising a roll frame formed of at least two spaced laminated roll rings, traverse members connecting said rings, said stand and roll frame having cooperating roller means axially and radially supporting the roll frame and furnace body, said roll frame and said furnace body having cooperating spring loaded first releasable means and recesses in which said first releasable means engage to fasten the furnace body in the roll frame, second releasable means mounted on the stand for engagement against the roll rings to hold the roll rings and furnace in the stand, said furnace body and said roll frame being vcrtically liftable away from the stand when said second releasable means is released, said furnace body with said roll frame being tiltable with said stand to positions with the furnace spout directed straight' downwards or upsaid standoin any position.

mounted on the base, a furnace,v body, andmeans rotat-` Y ably mounting the furnace body in said stand, compris-V ing a roll frame formed of at least two spaced laminated roll rings, traverse members connecting said rings, said 4. Rotatable furnace as claimed in claim 2, a rotating motor connected to the furnace arranged outside the stand, and gear` means in the stand, and turning rolls operably connected to the furnace body mounted in this stand, said gear means connecting Vsaid motor to said turning rolls.

5. Rotatable furnace as claimed in claim 2, in which the furnace body is provided with stiffening devices, the recesses being located in said stiffening devices.

6. Rotatable furnace as claimed in claim 2, in which the first releasable means comprise spring loaded pins Varranged in openings in the traverse members of the frame, said spring load comprising plate springs, vand a member secured in the opening for limiting the removal of the pins.

References Cited by the Examiner UNITED STATES PATENTS 2,132,948 io/ss Gottschalk 263-33A 2,767,971 10/,56 Hofmeister et al. 263-33 V3,031,177 4/62 Hofmeister 266-36 FOREIGN PATENTS i 776,962 6/57 Great Britain.

' 887,791 1/62 'Great Britain.

CHARLES SUKALo, Primary Examiner. 

1. ROTATABLE FURNACE INCLUDING A BASE, A STAND TILTABLY MOUNTED ON THE BASE, A FURNACE BODY, AND MEANS ROTATABLY MOUNTING THE FURNACE BODY IN SAID STAND, COMPRISING A ROLL FRAME FORMED OF AT LEAST TWO SPACED LAMINATED ROLL RINGS, TRAVERSE MEMBERS CONNECTING SAID RINGS, SAID STAND AND ROLL FRAME HAVING COOPERATING ROLLER MEANS AXIALLY AND RADIALLY SUPPORTING THE ROLL FRAME AND FURNACE BODY, THE ROLLER MEANS FOR RADIAL SUPPORT BEING ARRANGED AROUND THE FURNACE ALONG NOT MORE THAN 180* OF ITS PERIPHERY, SAID ROLL FRAME AND SAID FURNACE BODY HAVING COOPERATING SPRING LOADED RELEASABLE MEANS AND RECESSES IN WHICH SAID RELEASABLE MEANS ENGAGE TO FASTEN THE FURNACE BODY IN THE ROLL FRAME. 